//Sat 06 Feb 2010 10:48:36 AM CST 
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>

using namespace std;

class TheQuestionsAndAnswersDivTwo
{
public:
	int find(vector <string> questions)
	{
		int N = questions.size();
		set<string> st;
		int ret = 0;
		for(int i=0; i<N; i++)
		{
			int sz = st.size();
			st.insert(questions[i]);
			int szz = st.size();
			if(szz > sz) ret ++;
		}
		return (1<<ret);
	}
};
